Contents
Is there a way to nest fixed factors in GLMM?
The question comes as my fixed-factor Compo should be nested within SPrich but it seems that it is more common to nest random factors in glmm, and I have not encounter on how to nest fixed-factors.
How to model nested random factor with GLMM cross?
TankNo are denoted differently in all three ExpRun and therefore a nested random factor.
How to use GLMM for unbalanced zero inflated data?
See histogram: B: Sites in localities might show variation in intercepts due to higher initial snail abundance C: Sampling duration differed (5-33 minutes), which will most likely influence counts D: The number of sites per locality is unbalanced (one locality with only 1 site, overall range per locality: 1-9)
How is a nested factor conceptually random?
In a nested design, the nested factor is typically conceptually random, even though it might be fitted as a fixed effect (Factor 1 is a group-level predictor relative to Factor 2).
How to use glmer for nested data in R?
Given that my pathogen diversity data is count data with many zeros, which is why I have been exploring using using a GLMM with the lme4::glmer command in R to analyze the data. For the analysis I want to treat latitude as a numeric fixed factor and site as a random factor nested with location.
Is it hard to model nested fixed factor?
Really appreciate any thoughts on the above! Nested fixed effects are indeed hard to specify in linear models (as opposed to ANOVA frameworks), where the underlying framework is explicitly trying to estimate parameters rather than just evaluate sums of squares/proportions of variance explained.
Why do I use GLMM instead of tankno?
I go for GLMM because there is quite a large variance among different Tanks and thus masking the effect of factors that are of interests, and treating TankNo as a random factor should help lower the influence.
Can you do cross tabulation of nested factors?
If they are nested, you cannot because you do not have every combination of one factor along with every combination of the other. If you’re not sure whether two factors in your design are crossed or nested, the easiest way to tell is to run a cross tabulation of those factors. Here is an example.
When to include nesting factor as fixed effect?
It is really important to define what actually makes sense to include as fixed or random effects and what the grouping factors will be. This depends on how you designed the study and what you want to extract from your models. Thanks for contributing an answer to Cross Validated!